The gall's range is computed from the range of all hosts that the gall occurs on. In some cases we have evidence that the gall does not occur across the full range of the hosts and we will remove these places from the range. For undescribed species we will show the expected range based on hosts plus where the galls have been observed.
Our ID Notes may contain important tips necessary for distinguishing this gall
from similar galls and/or important information about the taxonomic status of
this gall inducer.
Created Feb 4, 2026 1:47 PM UTC
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Last updated Feb 4, 2026 1:47 PM UTC
The Gall Midges (Diptera: Cecidomyiidae) of Baccharis spp. (Asteraceae) in the United States
RJ Gagne, Paul E. Boldt.
(1995)
Rhopalomyia californica Felt
This species forms lobed, succulent, usually leafy bud galls (Fig. 3) on B. pilularis in California. It was imported into Australia as a potential biocontrol agent of B. halimifolia in 1969 and 1982. The gall midge took hold only after the 1982 introduction and since then has effectively established itself in Queensland and New South Wales (McFadyen 1985, Julien 1992, Palmer et al. 1993). It was also introduced into Texas in 1985 to control B. halimifolia and B. neglecta. Typical galls were observed on B. neglecta at Belton, Texas in 1986, but none was subsequently found (Boldt, unpub. data). The ecology of this species and its parasites has been investigated by Ehler (1982, 1987, 1992) and Ehler and Kinsey (1990, 1991, 1993). This species is very similar to Rhopalomyia sulcata Gagne. Differentiation between the two species is made under R. sulcata.
[Gagne here considers Rhopalomyia baccharis a junior synonym of R californica but this synonymy was later reversed]
